Improving the care of children with asthma is a national priority, evidenced by the inclusion of childhood asthma in the Healthy Children 2000 goals (Goal 11.1: reduce asthma hospitalizations). Certain groups of children are known to be at high risk for adverse asthma outcomes, which include acute exacerbations leading to emergency department visits, hospitalizations, and death. These children at high risk of adverse outcomes include children in urban settings, minorities, and poor children, the same populations traditionally served by Medicaid programs. In previous studies, careful management, involving patient education, written asthma plans, and directed use of asthma medications has been shown to improve clinical outcomes of children with asthma. However, lack of access to health care threatens a child s potential to receive proven effective interventions, which in turn threatens improvements in clinical outcomes. For high-risk children enrolled in Medicaid, gaps in enrollment are one potential threat to access to care. The proposed study is designed to quantify the effect of gaps in enrollment in Tennessee's Medicaid program for children with asthma using two clinical outcomes: emergency department visits and hospitalizations for asthma. A historical cohort study will be conducted using a long-standing Tennessee Medicaid research database. The cohort will include children meeting definitions of asthma based on health care encounters for asthma and filled prescriptions for asthma medications. Multivariate negative binomial regression controlling for sociodemographic characteristics and asthma severity will be used to determine if the rate of emergency department visits or hospitalizations is greater for children experiencing gaps in enrollment or children without gaps in enrollment. This evaluation will provide much needed information on the effects of specific policies or lack of policies (i.e. to ensure continuous enrollment for children with certain chronic illnesses) on clinical outcomes for high-risk children having one of the most common chronic health conditions in childhood. The evaluation will also increase general understanding of how threats to health care access potentially influence clinical outcomes in high-risk populations of children.